Hot air baker's rack ovens are known in which the goods which are to be baked are introduced on baking sheets arranged on square or rectangular trays or pans held in a quadratic wheeled rack. The rack is intended to be introduced into the oven chamber of the oven and to remain there while the baking process takes place. The oven chamber has a rectangular or square horizontal cross-section (i.e. the cross-section when viewed from above is rectangular or square) and is dimensioned to accept a rack and allow it to be rotated. Hot air can be introduced via one or two corner vents into the oven chamber to bake the goods. This leads to a temperature gradient across the oven chamber which can lead to uneven cooking of the goods. In order to reduce uneven baking of the goods, the rack is rotated around a vertical axis during the baking process. This can be achieved by placing the rack on a turntable during the baking process or by lifting the rack with a rotatable hook which is rotated during the baking process. Once the baking process is finished the rack is removed (after being lowered and decoupled from the hook if such a hook is used) from the open rack oven. An example of such a rack oven is known from U.S. Pat. No. 3,954,053. This has a substantially rectangular oven chamber with a straight back wall, two parallel, spaced-apart side walls arranged perpendicular to the back wall and a curved door able to close off the front end of the oven chamber.
Despite the use of rotating racks it is still not always possible to get an even temperature throughout the oven and uneven cooking of the goods often results.